The luxury crossover market has been a huge success for BMW, having sold over a million X3 models worldwide since the CUV first went on sale in 2003, not to mention all of the momentum its had with the larger X5. At the Chicago Auto Show, BMW is unveiling the refreshed 2015 X3, featuring an improved design, a new diesel engine option, and a rear-wheel drive variant.

The X3 is getting some handsome upgrades to the exterior. The twin, circular headlights now extend to touch the slightly widened, chrome kidney grille, to bring the styling in line with the 3 Series and 4 Series. (LED headlights are now optional, as well.) The front bumper gets reshaped brake cooling ducts, and the rear bumper gets a touch of additional metal trim at the bottom. BMW has also added standard LED turn signals in the side mirrors.

BMW has enhanced the interior with added chrome trim, high-gloss black trim around the center console, sliding covers for the cup holders and new interior upholstery designs. The X3 is also getting a major boost in optional technology - there's a new Parking Assistant, as well as an Active Driving Assistant with adaptive cruise control, Lane Departure Warning, Frontal Collision Warning, Pedestrian Warning, and City Collision Mitigation.

The biggest news for the X3 is the new xDrive28d version with BMW's 2.0-liter turbocharged diesel four-cylinder engine, pumping out 180 horsepower and 280 pound-feet of torque, and mated to an eight-speed automatic transmission. BMW claims that it will hit 60 miles per hour in just under eight seconds. Pricing for that model starts at $42,825, plus a $925 destination charge.

For the first time, there will also be an X3 without all-wheel drive. The new, rear-drive X3 sDrive28i will start at $39,325, plus $925 destination, and come with the 2.0-liter turbocharged, gasoline engine with 240 hp and 260 lb-ft. The sprint to 60 mph takes 6.2 seconds - the same as the all-wheel drive version. The X3 xDrive28i sees its price rise to $40,725, plus $925 destination, compared to $38,900 for the 2014 model, and the X3 xDrive35i now costs $45,825, plus $925 destination, compared to $44,900 for the 2014 version.